Method for collecting gaseous sample

ABSTRACT

The present invention of collecting a gaseous sample employs a sealable container, an inlet mounted at a part of the container, an outlet mounted at another part of the container, an atomizing electrode mounted in the container, a primary refrigerator mounted adjacent to the atomizing electrode, an opposite electrode mounted in the container, an acicular capture electrode mounted adjacent to the opposite electrode, and a secondary refrigerator mounted adjacent to the capture electrode. Charged microparticles are prepared by chilling the gaseous sample and producing condensate of the same. Such charged microparticles are collected by the capture electrode with static electricity, and they are condensed by chilling them. This method prevents the capture electrode from spreading solution thereon.

This application is a continuation of International Application No.PCT/JP2009/052255, whose international filing date is Feb. 4, 2009 whichin turn claims the benefit of Japanese Patent Application No.2008-024667, filed on Feb. 5, 2008, the disclosures of whichApplications are incorporated by reference herein. The benefit of thefiling and priority dates of the International and Japanese Applicationsis respectfully requested.

TECHNICAL FIELD

The present invention relates to a method for effectively collectinggaseous samples onto an electrode through electrostatic atomization.

BACKGROUND ART

Electrostatic atomization is well known in the art and has usually beenused to accumulate onto base plates a trace amount of the variouschemical substances like DNA, antibodies and proteins.

For example, the conventional electrostatic atomizer disclosed in PatentPublication 1 is an apparatus to spot or laminate onto base platesnon-volatile diluted biomolecule solution. FIG. 14 illustrates theconventional electrostatic atomizer. By applying several kV ofhigh-voltage between the capillary tubes 505 filled with proteinsolution and the dielectric layer 504, a mist of the protein solution issprayed onto the base plate 502 from the tips of the capillary tubes505.

Electrostatic atomizer illustrated in FIG. 14 accumulates any chemicalsolution at the desired positions 503 by controlling electricalconductivity in the dielectric layer 504 formed on the base plate 502 orgenerating a topical electric field with the hole at the dielectriclayer 504. This method was certainly effective in the manufacture ofthose so called DNA chips or protein chips wherein DNA or protein issequentially spotted or laminated onto base plates.

[Patent Citation 1]

Japanese Patent Provisional Publication No. 2002-511792 (Page 78, FIG.9, and optionally Page 31, Lines 12-13, FIGS. 3, 4 and 19)

[Patent Citation 2]

Japanese Patent Publication No. 3952052

[Patent Citation 3]

Japanese Patent Provisional Publication No. 7-190990 (in particular FIG.3)

[Patent Citation 4]

Japanese Patent Provisional Publication No. 7-270285 (in particularParagraphs of 0001 and 0008)

DISCLOSURE OF INVENTION Technical Problem

But when a capture electrode is made of a flat plate as taught by theprior art, electrostatically atomized solution is spread over the wholesurface of such electrode.

Technical Solution

In order to eliminate such problems known in the art, the presentdisclosure is directed to a method for collecting a gaseous sample withan electrostatic atomizer, wherein the electrostatic atomizer comprisesa sealable container, an inlet for the gaseous sample mounted at a partof the container, an outlet for the gaseous sample mounted at the otherpart of the container, an atomizing electrode mounted in the container,a primary refrigerator mounted adjacent to the atomizing electrode, anopposite electrode mounted in the container, an acicular captureelectrode opposed to the opposite electrode, and a secondaryrefrigerator mounted adjacent to the capture electrode, and the methodcomprises the steps of introducing the gaseous sample into the containerthrough the inlet, chilling the atomizing electrode with the primaryrefrigerator, preparing a primary condensate from the gaseous sample onan outer peripheral surface of the atomizing electrode, preparingcharged microparticles from the primary condensate with electrostaticatomization, applying voltage to the capture electrode for the oppositeelectrode, chilling the capture electrode with the secondaryrefrigerator, and preparing a secondary condensate from the chargedmicroparticles adjacent to the tip of the capture electrode.

It is preferable to complete the introduction of the gaseous sample onor before initiation of preparing charged microparticles.

Then, it is preferable to direct the tip of the capture electrodedownwardly into the container.

Further, it is preferable to chill the capture electrode with thesecondary refrigerator to the condensation point of water vapour orlower.

It is preferable to employ a thermoelectric element as the secondaryrefrigerator.

Further, it is preferable to change the chilling surface of thesecondary refrigerator to a heating surface by reversing the polarity ofdirect voltage to be applied to the thermoelectric element.

It is preferable to evaporate the secondary condensate by heating saidcapture electrode.

Further, it is preferable that the temperature of the opposite electrodeis maintained at the condensation point of water vapour or higher.

It is preferable that the charged microparticles comprise water andcomponents of the gaseous sample.

Further, it is preferable that components of the gaseous sample arevolatile organic compounds.

Further, it is preferable that the molecular weight of the volatileorganic compounds is from 15 g/mol or more to 500 g/mol or less.

It is preferable that the capture electrode possesses a mechanism toremove electrical charge with the charged microparticles.

Further, it is preferable that the capture electrode is able to connectto ground.

It is preferable that the tip of the capture electrode has a reservoirto receive the secondary condensate.

Further, it is preferable that the tip of the capture electrode isequipped with a detector for chemical substances.

It is preferable that an apparatus to assay biomolecules employs amethod for collecting gaseous sample.

These and other objects, additional aspects and advantages of thepresent disclosure will become apparent from the following detaileddescription on the preferred embodiments by referring to the drawingsattached hereto.

Advantageous Effects

According to the method for collecting gaseous samples of the presentdisclosure, since electrostatically atomized solution is concentrated atan area adjacent to the tip of the acicular capture electrode, suchelectrostatically atomized solution does not spread over the captureelectrode. Then, since the capture electrode is chilled by previouslyapplying voltage to the capture electrode, such electrostaticallyatomized solution also does not spread over the capture electrode.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 is an exemplary schematic view illustrating electrostaticatomizer according to Embodiment 1 of the present disclosure.

FIG. 2 is an exemplary schematic view illustrating a method forcollecting a gaseous sample according to Embodiment 1 of the presentdisclosure.

FIG. 3 is an exemplary schematic view illustrating a method forcollecting a gaseous sample according to Embodiment 1 of the presentdisclosure.

FIG. 4 is an exemplary schematic view illustrating a method forcollecting a gaseous sample according to Embodiment 1 of the presentdisclosure.

FIG. 5 is an exemplary schematic view illustrating a method forcollecting a gaseous sample according to Embodiment 2 of the presentdisclosure.

FIG. 6 is an exemplary schematic view illustrating a method forcollecting a gaseous sample according to Embodiment 2 of the presentdisclosure.

FIG. 7 is an exemplary schematic view illustrating a method forcollecting a gaseous sample according to Embodiment 2 of the presentdisclosure.

FIG. 8 is an exemplary schematic view illustrating a method forcollecting a gaseous sample according to Embodiment 3 of the presentdisclosure.

FIG. 9 is an exemplary schematic view illustrating a method forcollecting a gaseous sample according to Embodiment 3 of the presentdisclosure.

FIG. 10 is an exemplary schematic view illustrating a method forcollecting a gaseous sample according to Embodiment 3 of the presentdisclosure.

FIG. 11 is an exemplary schematic view illustrating a tail cone and amethod for producing charged microparticles.

FIG. 12 is an exemplary schematic view illustrating the captureelectrode 107 at the step of preparing secondary condensate and aphotograph thereon taken by a light microscope.

FIG. 13 is a graph illustrating an assay results on the secondarycondensate.

FIG. 14 is a schematic view illustrating the conventional electrostaticatomizer.

EXPLANATION OF REFERENCE Detailed Description

Embodiments of the present disclosure are described as follows withreference to the drawings attached hereto.

Embodiment 1

FIG. 1 is an exemplary schematic view illustrating a electrostaticatomizer according to Embodiment 1 of the present disclosure.

According to this embodiment, the electrostatic atomizer 100 isassembled from the following elements.

Container 101 is isolated from the outside thereof with a partition. Theshape of the container 101 may preferably be, but not limited to,rectangular parallelepiped form, polyhedron form, spindle form,spherical form or channel form. Then, with regard to the size of thecontainer 101, the volume of the container 101 should preferably besufficiently less than the total amount of the gaseous sample to beintroduced. For example, when 300 cc of the gaseous sample as the totalamount thereof is introduced, the volume of the container shouldpreferably be 6 cc or less. Further, materials for the container 101 arepreferably those which have less adsorbed gas or incorporated gas. Assuch, metal like stainless steel or aluminum is the most preferable, butinorganic materials like glass or silicon or plastics like acryl,polyethylene terephthalate or Teflon (Registered Trademark) may also beused. The container can also be made by employing some of thesematerials. In the meantime, the container 101 is preferable a hardstructure, but it may be soft or flexible, such as, an airbag, balloon,flexible tube or syringe.

Inlet 102 is mounted at a part of the container 101. Inlet 102 is usedto introduce the gaseous sample into the container 101. As the positionfor the inlet 102 to be mounted, any position can be used as long as itallows rapidly introducing the gaseous sample into the container 101.For example, when the shape of the container 101 is a rectangularparallelepiped form, the inlet should preferably be mounted at thecenter of the surface in the container 101 rather than the cornerthereof. Shape, size and material of the inlet 102 are not limited inthe present disclosure. As a shape of the inlet 102, the linear formlike that indicated in FIG. 1 or the other linear form comprising abranched space may be used. Further, one or more inlets 102 may bemounted to the container.

Outlet 103 is mounted at another part of the container 101. Outlet 103is used to exhaust the excessive gaseous sample, which saturate thecontainer 101. As a position for the outlet 103 to be mounted, anyposition can be used as long as it allows exhausting the excessivegaseous sample of those which saturate the container 101. Shape, sizeand material of the outlet 103 are not limited in the presentdisclosure. As a shape of the outlet 103, the linear form like thatindicated in FIG. 1 or the other linear form comprising a branched spacemay be used. Further, one or more outlets 103 may be mounted to thecontainer.

Atomizing electrode 104 is mounted in the container 101. Atomizingelectrode 104 is preferably mounted at a position where it is in thecontainer 101 and can be in contact with the gaseous sample. Forexample, it is preferably mounted at the center of the bottom of thecontainer 101. Minimizing the contact area between the atomizingelectrode 104 and the container 101 is preferable in view of reducingthermal conductivity.

The shape of the atomizing electrode 104 is preferably acicular in form.Length of the acicular electrode is preferably from 3 mm or more to 10mm or less. The diameter of the acicular electrode is preferably from0.5 mm or more to 1.0 mm or less. The diameter may be the same from thetip of the electrode to the root thereof. Alternatively, it may beuneven by reducing the diameter of the tip portion and maintaining thatof the root portion (i.e., the diameter narrows as the distance from theroot portion increases). One or more acicular electrodes may be mountedin the container.

Further, as materials for the atomizing electrode 104, good thermalconductive materials are preferable, in particular, metal is the mostpreferable. Especially, uncompounded metal like stainless steel, copper,brass, aluminum, nickel or tungsten may be used, otherwise, an alloy oran intermetallic compound made from two or more of the foregoinguncompounded metals may also be used. Further, in order to protect thesurface of the atomizing electrode 104, the electrode 104 may be coatedwith a film of chemically stable metal, such as, gold or platinum orwith the other good thermal conductive materials.

Primary refrigerator 105 is mounted adjacent to the atomizing electrode104. Primary refrigerator 105 chills the atomizing electrode 104. It ispreferable that the primary refrigerator 105 is a thermoelectricelement, but any heat pipe employing refrigerant carrier like water, airheat exchange element or cooling fan may also be used. Larger surfacearea to be chilled in the primary refrigerator 105 can effectively chillthe atomizing electrode 104. Accordingly, the size of the primaryrefrigerator 105 may be adjusted to realize the maximum contact areabetween that and the atomizing electrode 104, outer peripheral surfaceto be chilled in the primary refrigerator 105 may have rough structure,otherwise, the outer peripheral surface to be chilled in the primaryrefrigerator 105 may have porous structure. One or more the primaryrefrigerator 105 may be used.

In the meantime, the primary refrigerator 105 preferably contacts withthe atomizing electrode 104 directly, but it may also contact theelectrode 104 through a thermal conductive medium like thermalconductive sheet, thermal conductive resin, metal plate or grease. Then,the primary refrigerator 105 preferably contacts with the atomizingelectrode 104, but it may be separated occasionally therefrom withphysical or thermal means.

Opposite electrode 106 is opposite to the atomizing electrode 104.Opposite electrode 106 is used for electrostatic atomization incombination with the atomizing electrode 104. The distance between theopposite electrode 106 and the tip of the atomizing electrode 104 ispreferably from 3 mm or more to 4 mm or less. Toric shape is the mostpreferable for the opposite electrode 106. FIG. 1 illustrates thesectional view of the toric opposite electrode 106. It is mostpreferable to place the center of the toric opposite electrode 106 ontothe production of the acicular atomizing electrode 104 (i.e., centeredabout the vertical axis of the electrode 104). The shape of the oppositeelectrode 106 may be any polygon like rectangle or trapezoid. Inaddition, slit 106 a like through holes, wherein the chargedmicroparticles are passed through, may be formed in the oppositeelectrode 106. The thickness of the opposite electrode 106 is notlimited in the present disclosure. Further, the sectional area, theshape and the amount of the through holes are not limited in theopposite electrode in the present disclosure.

Metal is preferable as the material for the opposite electrode 106.Especially, uncompounded metal like iron, copper, zinc, chromium,aluminum, nickel or tungsten may be used, in addition, an alloy likestainless steel or brass, or an intermetallic compound comprising two ormore of the foregoing uncompounded metals may also be used. Further, inorder to protect the surface of the opposite electrode 106, the oppositeelectrode may be coated with a film of chemically stable metal like goldor platinum or with the other good thermal conductive materials.

Capture electrode 107 is mounted adjacent to the opposite electrode 106.The opposite electrode 106 is preferably mounted between the captureelectrode 107 and the atomizing electrode 104. Further through holes inthe capture electrode 107 and the opposite electrode 106 are preferablyaligned substantially linear with the atomizing electrode 104. Captureelectrode 107 is preferably mounted at the ceiling of the container 101,the atomizing electrode 104 is preferably mounted at the bottom of thecontainer 101, and the opposite electrode 106 is preferably mountedbetween the capture electrode 107 and the atomizing electrode 104.Capture electrode 107 is used to collect electrostatically atomizedcharged microparticles with static electricity.

The shape of the capture electrode 107 is preferably acicular form. Thelength of the acicular electrode is preferably from 3 mm or more to 10mm or less. The diameter of the acicular electrode is preferably from0.5 mm or more to 1.0 mm or less. The diameter may be the same from tipof the electrode to the root thereof. Alternatively, it may be uneven byreducing the diameter of the tip portion and maintaining that of theroot portion (i.e., the diameter narrows as the distance from the rootportion increases). The distance between the tip of the captureelectrode 107 and the opposite electrode 106 is not limited in thepresent disclosure. Further, as materials for the capture electrode 107,good thermal conductive materials are preferable, in particular, metalis the most preferable. Especially, uncompounded metal like iron,copper, zinc, chromium, aluminum, nickel or tungsten may be used, inaddition, an alloy like stainless steel or brass, or an intermetalliccompound comprising two or more of the foregoing uncompounded metals mayalso be used. Further, in order to protect the surface of the captureelectrode 107, the capture electrode 107 may be coated with a film ofchemically stable metal, such as, gold or platinum or with the othergood thermal conductive materials.

Further, since the electrical field is preferably concentrated at thetip of the capture electrode 107, the shape of the capture electrode maybe formed in a conical shape, square pyramid or trigonal pyramid, orotherwise in some other sharp shape. Most preferably acicular captureelectrode 107 is solid, but it may be hollow, such as, a pipe. One ormore the capture electrodes 107 may be used.

Further, the tip of the capture electrode 107 is preferably mounted soas to extend downwardly into the container. As such, theelectrostatically atomized solution tends to move toward the tip due togravity.

Secondary refrigerator 108 is mounted adjacent to the capture electrode107. Secondary refrigerator 108 is used to chill the capture electrode107. Most preferably the secondary refrigerator 108 is a thermoelectricelement, but any heat pipe employing refrigerant carrier like water, airheat exchange element and cooling fan may also be used. Larger surfacearea to be chilled in the secondary refrigerator 108 can effectivelychill the capture electrode 107. Accordingly, the size of the secondaryrefrigerator 108 may be adjusted to realize the maximum contact areabetween that and the capture electrode 107. The outer peripheral surfaceto be chilled in the secondary refrigerator 108 may have a roughstructure, otherwise, the outer peripheral surface to be chilled in thesecondary refrigerator 108 may have a porous structure. One or more thesecondary refrigerators 108 may be used.

The secondary refrigerator 108 preferably contacts the capture electrode107 directly, but it may also contact the capture electrode 107 througha thermal conductive medium like a thermal conductive sheet, a thermalconductive resin, a metal plate or grease. The, the secondaryrefrigerator 108 preferably contacts the capture electrode 107 usually,but it may be separated occasionally therefrom with physical or thermalmeans.

Although it is most preferable for the secondary refrigerator 108 andthe primary refrigerator 105 to be controlled individually, a singlerefrigerator may be used as both the primary refrigerator 105 and thesecondary refrigerator 108. Size, kind and amount of the primaryrefrigerator 105 may be identical to or be different from those of thesecondary 108 refrigerator.

Valves 109 a and 109 b are preferably mounted at the inlet 102 and theoutlet 103. Container 101 can preferably be sealed with such valves 109a and 109 b. Materials, position and kinds of the valves 109 a and 109 bare not limited in the present disclosure. Further, when conductance ofthe valves 109 a and 109 b is minimal, the container 101 is regarded asessentially sealed.

FIGS. 2-4 are exemplary schematic views illustrating a method forcollecting the gaseous sample according to Embodiment 1 of the presentdisclosure. The same symbols were allocated to the elements in FIGS. 2-4according to the corresponding identical elements in FIG. 1 and anydescription of such elements has been omitted.

First of all, the gaseous sample 203 consisting of water 201 andchemical substance 202 a, 202 b is introduced into the container 101through the inlet 102. FIG. 2 (a) illustrates introducing a gaseoussample. A gaseous sample detector may be mounted in the container 101 toconfirm whether or not the container 101 is filled with the gaseoussample 203. One or more gaseous sample detectors can be mounted.According to the present disclosure, any kind and position of thegaseous sample detector can be employed.

During introduction of the gaseous sample, the gaseous sample 203 ispreferably placed into the container 101 from the inlet 102, though thegaseous sample may also be placed into the container by depressurizingthe outlet 103.

Further, during introduction of the gaseous sample, prior to introducingof the gaseous sample 203 into the container 101, the container 101 ispreferably filled with fresh air. Container 101 may be filled with drynitrogen gas or other inactive gas, otherwise it may be filled withstandard gas or calibration gas where their humidity is equivalent tothat of the gaseous sample.

Then, during introduction of the gaseous sample, excessive gaseoussample 203 is exhausted through outlet 103.

Introduction and exhaustion of the gaseous sample 203 during theintroduction of the gaseous sample are controlled by the valve 109 a andthe valve 109 b. A trap may be mounted at the inlet 102 so as not tointroduce unnecessary products.

For convenience sake, FIG. 2 (a) does not include any substance exceptfor chemical substances 202 a, 202 b, but the gaseous sample 203 mayincludes two or more components.

Then, during production of the primary condensate, the atomizingelectrode 104 is chilled by the primary refrigerator 105. FIG. 2 (b)illustrates production of the primary condensate. According to FIG. 2(b), the primary refrigerator 105 is connected to direct power toillustrate an image of chilling the atomizing electrode 104 by theprimary refrigerator 105. But the present disclosure is not limited tosuch direct power on the primary refrigerator 105 during production ofthe primary condensate.

By producing the primary condensate after such introduction of thegaseous sample, any condensation on all the substances except for suchgaseous sample can be controlled. During production of the primarycondensate, it is preferable to decrease the thermal conductivity so asnot to chill any part except for the atomizing electrode 104, forexample, the container 101. In order to decrease the thermalconductivity, it is most preferable to reduce the contact area betweenthe atomizing electrode 104 and the container 101. Otherwise, anymaterial having a lower coefficient of thermal conductivity may bedisposed at the contact space between the atomizing electrode 104 andthe container 101.

Then, during production of the primary condensate, the primarycondensate 204 comprising water 201, the chemical substance 202 a andthe chemical substance 202 b are formed on the outer peripheral surfaceof the chilled atomizing electrode 104. FIG. 2 (c) illustrates theproducing of the primary condensate.

During production of the primary condensate, it is preferable to controlthe temperature of the atomizing electrode 104 with the primaryrefrigerator 105 so as to not generate an excess amount of the primarycondensate 204.

Then, during production of the charged microparticles, numerous chargedmicroparticles 205 are formed from the primary condensate 204. FIG. 3(a) illustrates producing the charged microparticles. Such chargedmicroparticles are most preferably microparticles consisting of severalthousand molecules, but they may be single through several hundred ofclusters or be several ten thousand liquid droplets. Two or more ofthose may be used simultaneously.

Charged microparticles 205 may also include ions or radicals fromchemical substances in addition to electrically neutral molecules. Theymay be used simultaneously. Charged microparticles 205 are preferablycharged negatively, but they may be charged positively.

The most preferable method to produce the charged microparticles is anelectrostatic atomization. The principle of the electrostaticatomization is briefly noted herein. Primary condensate 204 istransferred to the tip of the atomizing electrode 104 by the voltageapplied between the atomizing electrode 104 and the opposite electrode106. The liquid level of the primary condensate 204 is conically raisedtoward the opposite electrode 106 by coulomb attraction. Such conicallyraised liquid is called a Taylor cone. When the condensate is furthergrown at the outer peripheral surface of the atomizing electrode 104,the conical primary condensate 204 is also grown and electrical chargesare concentrated at the tip of the primary condensate 204, thereby, suchcoulomb attraction is enhanced. When such coulomb attraction is inexcess of the surface tension of water, the primary condensates 204 arebroken and dispersed, then the charged microparticles 205 are formed.This is the principle of the electrostatic atomization.

During production of the charged microparticles, a voltage of from 4 kVor more to 6 kV or less is preferably applied between the atomizingelectrode 104 and the opposite electrode 106.

The diameter of the charged microparticles 205 is not particularlylimited according to the present disclosure, but it is preferablyrestricted to the range of from 2 nm or more to 30 nm or less in view ofstability of the charged microparticles.

An electrical amount to be charged to the charged microparticles 205 ismost preferably an amount equivalent to the electrical charge content(1.6×10⁻¹⁹ C) per the single microparticle, but such amount can bechanged to that larger than the electrical charge content.

Then, during application of the voltage, the voltage is applied to thecapture electrode 107 for the opposite electrode 106. FIG. 3 (b)illustrates application of the voltage. Charged microparticles 205having the diameter of from about 2 nm to about 30 nm tend to bedispersed because they are repulsed by static electricity, but most ofthe charged microparticles 205 are easily concentrated adjacent to thetip of the capture electrode 107 by providing the acicular captureelectrode 107 and concentrating static electricity thereto. When thecharged microparticles 205 are negatively charged, it is preferable toapply direct positive voltage to the capture electrode 107 for theopposite electrode 106. Application of the voltage is preferablycontinuous, but it may also be applied in a pulsed mode.

Then, during production of the secondary condensate, the captureelectrode 107 is chilled by the secondary refrigerator 108. FIG. 3 (c)illustrates production of the secondary condensate. By producing thesecondary condensate after such application of voltage, chargedmicroparticles 205 are concentrated adjacent to the tip of the captureelectrode 107 and can be chilled.

Then, during production of the secondary condensate, most of the chargedmicroparticles 205 are condensed adjacent to the tip of the captureelectrode 107, then the secondary condensates 206 are formed. FIG. 4illustrates producing the secondary condensate. As a result of producingthe secondary condensate, it prevents the capture electrode 107 fromspreading the secondary condensate 206 on the whole surface thereof.

According to the embodiment of the present disclosure, it is preferableto chill the capture electrode 107 with the secondary refrigerator 108to the condensation point of water vapour or lower. The temperature ofthe capture electrode 107 may be measured with a thermometer mountedadjacent to the capture electrode 107. Temperature of the captureelectrode 107 may also be controlled.

Then, according to the embodiment of the present disclosure, it ispreferable to heat the capture electrode 107 to evaporate the secondarycondensate 206. The temperature of the heated capture electrode 107 ispreferably the condensation point of water vapour or higher. Thereby,the gaseous sample is not condensed on the capture electrode 107 atunwanted times.

Further, according to the embodiment of the present disclosure, it ispreferable to change the surface to be chilled in the secondaryrefrigerator 108 into the heating surface by reversing the polarity ofthe voltage to be applied to the thermoelectric element. Thereby, sincethe capture electrode 107 can be heated, the secondary condensate 206can be easily evaporated.

According to the embodiment of the present disclosure, it is preferableto maintain the temperature of the opposite electrode 106 at thecondensation point of water vapour or higher. By maintaining thetemperature of the opposite electrode 106 at the condensation point ofwater vapour or higher, the charged microparticles 205 would not becondensed on the outer peripheral surface of the opposite electrode 106.In order to maintain the temperature of the opposite electrode 106 atthe condensation point of water vapour or more, any heating unit may bemounted at the opposite electrode 106.

Charged microparticles 205 preferably comprise water 201 together withthe chemical substances 202 a, 202 b which are components of the gaseoussample. The weight ratio of water and the gaseous sample components inthe charged microparticles may be identical to that of water and gaseoussample components in the gaseous sample or may be different therefrom.

Then, according to the embodiment of the present disclosure, thecomponent of the gaseous sample is preferably volatile organic compounds(particularly, volatile organic compounds having a molecular weight offrom 15 g/mol or more to 500 g/mol or less). Such volatile organiccompounds may preferably include ketone, amine, alcohol, aromatichydrocarbon, aldehyde, ester, organic acid, hydrogen sulfide, methylmercaptan and disulfide. Otherwise, these substances or alkane, alkene,alkyne, diene, cycloaliphatic hydrocarbon, allene, ether, carbonyl,carbanion, protein, polynuclear aromatic, heterocyclic, organicderivative, biomolecule, metabolite, isoprene, isoprenoid and derivativethereof may also be used.

Further, according to the embodiment of the present disclosure, thecapture electrode 107 is preferably destaticized. For example, when thecharged microparticles 205 are charged negatively, the capture electrode107 will also be charged negatively according to gaseous samplecomponents collected at capture electrode 107. Since it will bedifficult to collect the charged microparticles 205 adjacent to the tipof the capture electrode 107 when the charged amounts thereof areexcessive, any destaticization system should preferably be provided.Such destaticization may be conducted continuously or optionally.

According to the embodiment of the present disclosure, the captureelectrode 107 is preferable able to connect to ground to destaticize(i.e., electrically neutralize) the capture electrode. Any connectionmethod for connecting the capture electrode 107 to ground can beemployed in the present disclosure.

Further, according to the embodiment of the present disclosure, it ispreferable to provide a reservoir 110 to store the secondary condensate206 at the tip of the capture electrode 107. By providing the reservoir110 at the tip of the capture electrode 107, the secondary condensate206 does not spread over the whole surface of the capture electrode 107.The reservoir may have a rough structure at the tip of the captureelectrode 107. By providing such a rough structure, the contact areabetween the structure and the secondary condensate 206 is increased,thereby the liquid is stored therein. The shape of the reservoir 110 mayinclude, but is not limited to, a globular form, a spindle form, andother polygonal forms. When the reservoir 110 is in the shape of aglobular form, the diameter thereof is preferably in the range of from 1mm or more to 2 mm or less. The reservoir 110 may comprise any waterabsorbent, such as, porous material, nanofoam and gel. The outerperipheral surface of the tip of the capture electrode 107 may also besubjected to hydrophilic treatment. As such a hydrophilic treatment,hydrophilic materials like glass and titanium oxide may be formed into afilm. Alternatively, any organic molecule having hydrophilic group likesilanol group, carboxyl group, amino group and phosphoric group at theterminal thereof may be absorbed or be bound.

Further, according to the embodiment of the present disclosure, it ispreferable to provide a chemical substance detector 111 at the tip ofthe capture electrode 107. As such a chemical substance detector 111, inaddition to a gas chromatograph, other chemical substance detectors mayalso be utilized. For example, a sensor like MOSFET(Metal-Oxide-Semiconductor Electric Field Transistor), ISFET (IonSensitive Electric Field Transistor), Bipolar Transistor, Organic ThinLayer Transistor, OPTODE, Metal Oxide Semiconductor Sensor, QuartzCrystal Microbalance (QCM), Surface Acoustic Wave (SAW) Element, SolidElectrolyte Gas Sensor, Electrochemical Cell Sensor, Surface WavePlasmon Resonance (SPR), Langmuir-Blodgett Film (LB Film) Sensor may beused. Alternatively, High Performance Liquid Chromatograph, MassSpectrometer, Nuclear Magnetic Resonance Spectrometer, LC-IT-TOFMS,SHIFT-MS may also be used. In addition, one or more chemical substancedetectors may be mounted in the container. Further, when two or morechemical substance detectors are used, a single type of the detector maybe used, while multiple types thereof may also be used in combinationwith one another. Any acceptable means for transferring the secondarycondensate 206 between the capture electrode 107 and the chemicalsubstance detector may be provided.

According to the embodiment of the present disclosure, an assayapparatus for biomolecules may employ the present method for collectingthe gaseous sample. Such biomolecules preferably include ketone, amine,alcohol, aromatic hydrocarbon, aldehyde, ester, organic acid, hydrogensulfide, methyl mercaptan and disulfide. Alternatively, alkane, alkene,alkyne, diene, cycloaliphatic hydrocarbon, allene, ether, carbonyl,carbanion, protein, polynuclear aromatic, heterocyclic, organicderivative, biomolecule, metabolite, isoprene, isoprenoid andderivatives thereof may also be used. Other biological organic compoundsmay also be utilized.

According to the embodiment of the present disclosure, the chargedmicroparticles 205 are concentrated adjacent to the tip of the acicularcapture electrode 107 during application of a voltage to preventcondensate from spreading at an electrode to capture it and are chilledsecondary, thereby, the secondary condensate 206 are duly produced.Concentration of the secondary condensate 206 to be realized bysecondary chilling of the charged microparticles after application ofvoltage is larger than that to be realized by secondary chilling thecharged microparticles prior to application of voltage.

It is noted that the present embodiment is quite different from theconventional generator for negatively charged mist relied onelectrostatic atomization. Namely, the diameter of chargedmicroparticles produced by such a conventional mist generator is verysmall and is in a range of from several nm to several ten nm. Chargedmicroparticles in nanometer size tend to (1) float in air for the longerperiods of about 10 minutes and (2) easily spread. Such properties inthe negatively charged mist are advantageous in a humectant apparatus ordeodorant apparatus for skin and hair. But such properties aredisadvantageous when collecting the chemical substances according to thepresent disclosure. Accordingly, prior to the present disclosure, therehas been no reason to use an electrostatic atomization method whichproduces the charged microparticles in nanometer size to collect thechemical substances. However, by utilizing the method of thisembodiment, such chemical substances can be effectively captured, evenif the charged microparticles in nanometer size tend to float or spread.

Further, according to the embodiment of the present disclosure, thecontainer 101 is made of plastics, Teflon (Registered Trademark) is themost preferable, while acrylic resin, polyethylene terephthalate (PET),polyester, fluorine plastics or PDMS may also be used. When thecontainer 101 is made of plastic, it is more preferable to coat ametallic film onto the inner surface of the container 101. As such ametallic film, aluminum film is the most preferable in view of its lowercost and its ideal gas barrier properties, but the other metallic filmsmay also be used. Further, two or more of such metal films may be usedsimultaneously.

According to the embodiment of the present disclosure, when thecontainer 101 is made of inorganic materials, any inorganic matter, suchas, silica glass, borosilicate glass, silicon nitride, alumina andsilicon carbide may be used, and those wherein a thin film made ofinsulating material is coated on silicon surface with silicon dioxide,silicon nitride or tantalum oxide may also be used. Further, two or moreof these may be used simultaneously.

Further, the valve 109 a and the valve 109 b mounted at the inlet 102and the outlet 103 may be equipped with a control valve, such as, acheck valve or a stop valve to control flow of the gaseous sample.

Then, an instrument to determine flow rate of the gaseous sample may bemounted at the inlet 102 and the outlet 103. As the instrument, anintegrating flowmeter or mass flowmeter may be used. Alternatively, anysuitable flow instrument may be utilized.

Further, during introduction of the gaseous sample, when pressure isapplied to the inlet 102, an electric power pump, such as, a diaphragmpump, peristaltic pump or syringe pump may be used. Alternatively, thegaseous sample may be introduced manually with a syringe or dropper.

During introduction of the gaseous sample, pressure may also be drawnfrom the outlet 103 using an electric power pump, such as, a diaphragmpump, peristaltic pump or syringe pump Alternatively, as noted thegaseous sample may be introduced manually with a syringe or dropper.

Further, a heat dissipation fin may be mounted at a heat dissipationarea in the primary refrigerator 105 and the secondary refrigerator 108.Alternatively, the heat dissipation area may be chilled with water, air,a thermoelectric element or other suitable methods. In addition, two ormore of these techniques may be used simultaneously.

Although the atomizing electrode 104 preferably employs metal, anymaterial which has good electrical conductivity or good thermalconductivity may also be utilized.

According to the embodiment of the present disclosure, one or moreatomizing electrodes 104 may be used. When plural atomizing electrodes104 are used, they may be arranged one dimensionally, such as, linearly,two dimensionally, such as, circularly, parabolic, ovally, tetragonallattice form, rhombic lattice form, closest packing lattice form,radially, randomly, or three dimensionally like spherically, paraboliccurved form or ovally curved form.

Although the capture electrode 107 preferably employs metal, anymaterial which has good electrical conductivity or good thermalconductivity may also be utilized.

Further, according to the embodiment of the present disclosure, one ormore capture electrode 107 may be used. When plural capture electrodes107 are used, they may be arranged one dimensionally, such as, linearly,two dimensionally, such as, circularly, parabolic, ovally, tetragonallattice form, rhombic lattice form, closest packing lattice form,radially, randomly, or three dimensionally, such as, spherically,parabolic curved form or ovally curved form.

Embodiment 2

FIGS. 5-7 are exemplary schematic views illustrating a method forcollecting gaseous samples according to Embodiment 2 of the presentdisclosure. The same symbols were allocated to the elements in FIGS. 5-7according to the corresponding identical elements in FIGS. 1-4 and anydescription of such elements has been omitted.

First, the gaseous sample 203 consisting of water 201 and chemicalsubstance 202 a, 202 b is introduced into the container 101 through theinlet 102. FIG. 5 (a) illustrates the introduction of the gaseoussample. Gaseous sample detector may be mounted in the container 101 toconfirm whether or not the container 101 is filled with the gaseoussample 203. One or more gaseous sample detectors can be mounted.According to the present disclosure, any kind and position of thegaseous sample detectors can be utilized.

During introduction of the gaseous sample, the gaseous sample 203 ispreferably placed into the container 101 from the inlet 102, though thegaseous sample may be placed into the container by depressurizing theoutlet 103.

Further, during introduction of the gaseous sample, prior to introducingthe gaseous sample 203 into the container 101, the container 101 ispreferably filled with fresh air. Container 101 may be filled with drynitrogen gas or the other inactive gas. Alternatively, it may be filledwith standard gas or calibration gas wherein the humidity is equivalentto that of the gaseous sample.

Then, during introduction of the gaseous sample, excessive gaseoussample 203 is exhausted through outlet 103.

Introduction and exhaustion of the gaseous sample 203 duringintroduction of the gaseous sample is controlled by the valve 109 a andthe valve 109 b. Traps may be mounted at the inlet 102 so as not tointroduce unnecessary products.

For convenience sake, FIG. 5 (a) does not include any substance exceptfor chemical substances 202 a, 202 b, but the gaseous sample 203 mayinclude two or more components.

Then, during production of the primary condensate, the atomizingelectrode 104 is chilled by the primary refrigerator 105. FIG. 5 (b)illustrates production of the primary condensate. By producing theprimary condensate after introduction of the gaseous sample, anycondensation on the substances except for such gaseous sample can becontrolled. During the producing of the primary condensate, it ispreferable to decrease thermal conductivity so as not to chill any partexcept for the atomizing electrode 104, for example, the container 101.In order to decrease the thermal conductivity, it is preferable toreduce the contact area between the atomizing electrode 104 and thecontainer 101. Alternatively, any material having a reduced coefficientof thermal conductivity may be disposed at the contact space between theatomizing electrode 104 and the container 101.

Then, during production of the primary condensate, the primarycondensate 204 comprising water 201, the chemical substance 202 a andthe chemical substance 202 b are formed on the outer peripheral surfaceof the chilled atomizing electrode 104. FIG. 5 (c) illustratesproduction of the primary condensate.

When producing of primary condensate, it is preferable to appropriatelycontrol the temperature of the atomizing electrode 104 with the primaryrefrigerator 105 so as not to generate an excess amount of the primarycondensate 204.

According to the embodiment of the present disclosure, when the primarycondensate 204 is fully produced during production of the primarycondensate, the valve 109 a and the valve 109 b are closed. Thereafter,air can not communicate between the inner chamber of the container 101and the outside of the container.

Then, during production of the charged microparticles, numerous chargedmicroparticles 205 are formed from the primary condensate 204. FIG. 6(a) illustrates production of the charged microparticles. Such chargedmicroparticles are most preferably microparticles consisting of severalthousand molecules, but they may be single through several hundredclusters or be several ten thousand liquid droplets. In additiona, twoor more of these may be used simultaneously.

Black valves 109 a and 109 b in FIG. 6 (a) indicated that the valves areclosed.

Charged microparticles 205 may also include ions or radicals fromchemical substances in addition to electrically neutral molecules. Theymay be used simultaneously. Charged microparticles 205 are preferablycharged negatively, but they may be charged positively.

During production of the charged microparticles, a voltage of from 4 kVor more to 6 kV or less is preferably applied between the atomizingelectrode 104 and the opposite electrode 106.

The diameter of the charged microparticles 205 is not particularlylimited according to the present disclosure, but the diameter isrestricted preferably to the range of from 2 nm or more to 30 nm or lessin view of stability of the charged microparticles.

An electrical amount to be charged to the charged microparticles 205 ismost preferably an amount equivalent to the electrical charge content(1.6×10⁻¹⁹ C) per the single microparticle, but such amount can bechanged to be larger than the electrical charge content.

Then, during application of the voltage, voltage is applied to thecapture electrode 107 for the opposite electrode 106. FIG. 6 (b)illustrates applying of the voltage. Charged microparticles 205 havingthe diameter of from about 2 nm to about 30 nm tend to be dispersedbecause they are repulsed by static electricity, but most of the chargedmicroparticles 205 are easily concentrated adjacent to the tip of thecapture electrode 107 by providing the acicular capture electrode 107and concentrating static electricity at the capture electrode. When thecharged microparticles 205 are negatively charged, it is preferable toapply direct positive voltage to the capture electrode 107 for theopposite electrode 106. Application of the voltage is preferablycontinuous, but it may be applied in a pulsed manner.

Then, during production of the secondary condensate, the captureelectrode 107 is chilled by the secondary refrigerator 108. FIG. 6 (c)illustrates the producing of the secondary condensate. By producing thesecondary condensate after application of the voltage, chargedmicroparticles 205 are concentrated adjacent to the tip of the captureelectrode 107 and can be chilled.

When producing the secondary condensate, most of the chargedmicroparticles 205 are condensed adjacent to the tip of the captureelectrode 107, and the secondary condensates 206 are formed. FIG. 7illustrates production of the secondary condensate. As a result ofproducing of the secondary condensate, it prevents the capture electrode107 from spreading the secondary condensate 206 on the whole surfacethereof.

In the meantime, according to the embodiment of the present disclosure,the container 101 is sealed after production of the chargedmicroparticles. Accordingly, motion of the charged microparticles 205would not be disturbed by air flow generated when introducing thegaseous sample 203. This is because motion of the charged microparticles205 preferably relies mainly on static electricity. As a result, thecharged microparticles 205 can easily be concentrated at the tip of thecapture electrode 107.

Embodiment 3

FIGS. 8-10 are exemplary schematic views illustrating a method forcollecting the gaseous sample according to Embodiment 3 of the presentdisclosure. The same symbols were allocated to the elements in FIGS.8-10 according to the corresponding identical elements in FIGS. 1-4 andany description of such elements has been omitted.

First, the gaseous sample 203 consisting of water 201 and chemicalsubstance 202 a, 202 b is introduced into the container 101 through theinlet 102. FIG. 8 (a) illustrates the introducing of the gaseous sample.Gaseous sample detector may be mounted in the container 101 to confirmwhether or not the container 101 is filled with the gaseous sample 203.One or more gaseous sample detectors may be mounted and utilized.According to the present disclosure, any suitable kind and position ofthe gaseous sample detector can be utilized.

During introduction of the gaseous sample, the gaseous sample 203 ispreferably placed into the container 101 from the inlet 102, though thegaseous sample may also be placed into the container by depressurizingthe outlet 103.

Further, during introduction of the gaseous sample, prior to introducingthe gaseous sample 203 into the container 101, the container 101 ispreferably filled with fresh air. Container 101 may be filled with drynitrogen gas or another inactive gas. Alternatively, it may be filledwith standard gas or calibration gas where their humidity is equivalentto that of the gaseous sample.

Then, during introduction of the gaseous sample, any excessive gaseoussample 203 is exhausted through outlet 103.

Introduction and exhaustion of the gaseous sample 203 duringintroduction of the gaseous sample are controlled by the valve 109 a andthe valve 109 b. Traps may be mounted at the inlet 102 so as to preventthe introduction of unnecessary products.

For convenience sake, FIG. 8 (a) does not include any substance exceptfor chemical substances 202 a, 202 b, but the gaseous sample 203 mayincludes two or more components.

According to the embodiment of the present disclosure, when the gaseoussample 203 is uniformly saturated during the introducing thereof, thevalve 109 a and the valve 109 b are then closed. Thereafter, air can notcommunicate between the inner chamber of the container 101 and theoutside of the container 101.

Then, during the production of the primary condensate, the atomizingelectrode 104 is chilled by the primary refrigerator 105. FIG. 8 (b)illustrates production of the primary condensate. By producing theprimary condensate after introduction of the gaseous sample, anycondensation on the substances except for such gaseous sample can becontrolled. During production of the primary condensate, it ispreferable to decrease thermal conductivity so as not to chill any partexcept for the atomizing electrode 104, for example, the container 101.In order to decrease the thermal conductivity, it is most preferable toreduce the contact area between the atomizing electrode 104 and thecontainer 101. Alternatively, any material having a low coefficient ofthermal conductivity may be disposed at the contact space between theatomizing electrode 104 and the container 101.

Then, during production of the primary condensate, the primarycondensate 204 comprising water 201, the chemical substance 202 a andthe chemical substance 202 b are formed on the outer peripheral surfaceof the chilled atomizing electrode 104. FIG. 8 (c) illustrates theproduction of the primary condensate.

During production of the primary condensate, it is preferable to controlthe temperature of the atomizing electrode 104 with the primaryrefrigerator 105 so that an excess amount of the primary condensate 204is not generated.

Then, during production of the charged microparticles, numerous chargedmicroparticles 205 are formed from the primary condensate 204. FIG. 9(a) illustrates production of the charged microparticles. Such chargedmicroparticles are most preferably microparticles consisting of severalthousand molecules, but they may be single through several hundredclusters or be several ten thousand liquid droplets. In addition, two ormore of these may be used simultaneously.

Charged microparticles 205 may also include ion or radical from chemicalsubstances in addition to electrically neutral molecules. They may beused simultaneously. Charged microparticles 205 are preferably chargednegatively, but they may be charged positively.

During production of the charged microparticles, a voltage of from 4 kVor more to 6 kV or less is preferably applied between the atomizingelectrode 104 and the opposite electrode 106.

The diameter of the charged microparticles 205 is not particularlylimited according to the present disclosure, but it is restrictedpreferably to the range of from 2 nm or more to 30 nm or less in view ofstability of the charged microparticles.

An electrical amount to be charged to the charged microparticles 205 ismost preferably an amount equivalent to the electrical charge content(1.6×10⁻¹⁹ C) per the single microparticle, but such an amount can bechanged to be larger than the electrical charge content.

According to the embodiment of the present disclosure, the container 101is sealed after production of the primary condensate. Thereby, thecharged microparticles 205 can not flow away from the container 101.

Then, during application of the voltage, the voltage is applied to thecapture electrode 107 for the opposite electrode 106. FIG. 9 (b)illustrates application of the voltage. Charged microparticles 205having the diameter of from about 2 nm to about 30 nm tend to bedispersed because they are repulsed by static electricity, but most ofthe charged microparticles 205 are readily concentrated adjacent to thetip of the capture electrode 107 by providing the acicular captureelectrode 107 and concentrating static electricity at the captureelectrode 107. When the charged microparticles 205 are negativelycharged, it is preferably to apply direct positive voltage to thecapture electrode 107 for the opposite electrode 106. Application of thevoltage is preferably continuous, but it may also be applied in a pulsedmanner.

Then, during production of the secondary condensate, the captureelectrode 107 is chilled by the secondary refrigerator 108. FIG. 9 (c)illustrates production of the secondary condensate. By producing thesecondary condensate after application of the voltage, chargedmicroparticles 205 are concentrated adjacent to the tip of the captureelectrode 107 and can be chilled.

Then, during production of the secondary condensate, most of the chargedmicroparticles 205 are condensed adjacent to the tip of the captureelectrode 107, and then the secondary condensates 206 are formed. FIG.10 illustrates the producing of the secondary condensate. As a result ofproducing the secondary condensate, it prevents the capture electrode107 from spreading the secondary condensate 206 on the whole surfacethereof.

Since the gaseous sample 203 is electrically neutral, it may be directlychanged into condensate without producing the charged microparticles atnot only the tip of the acicular capture electrode 107 but also at theside surface thereof. But, according to the embodiment of the presentdisclosure, since the container 101 is sealed after the primarycondensate has been produced, the gaseous sample 203 would notadditionally be introduced thereinto. Accordingly, it would be difficultto form condensate directly from the gaseous sample 203 on the captureelectrode 107 and to spread the same on the whole surface of the captureelectrode 107.

Further, according to the embodiment of the present disclosure, thecharged microparticles 205 do not flow away from the container 101. Atthis time, since the number of the charged microparticles 205 in thecontainer 101 would be increased, the secondary condensate 206 isconcentrated at the tip of the capture electrode 107. As a resultthereof, the present disclosure prevents the capture electrode 107 fromspreading condensate on the whole surface thereof.

Example 1

Container 101 was made of transparent acrylic resin of 0.5 mm thickness.The container 101 was rectangular parallelepiped having dimensions of 32mm×17 mm×12 mm. Transparent container 101 is preferable, because theprocess of forming condensate can be observed. In such a case, thecontainer 101 can be made through monolithic molding.

Inlet 102 was made by forming a hole of 3 mm diameter at a part of thecontainer 101 and connecting therewith a silicone tube of 3 mm outerdiameter. Inlet 102 can be made by any method known in the art. Namely,it can be made by any method including monolithic molding to be employedto form it together with the container 101, cutting operation, and theother conventional forming methods like dry etching, hot embossing andnanoimprint.

Outlet 103 was made by forming a hole of 3 mm diameter at another partof the container 101 and connecting therewith a silicone tube of 3 mmouter diameter. Outlet 103 can be made by any method known in the art.Namely, it can be made by any method including monolithic molding to beemployed to form it together with the container 101, cutting operation,and the other conventional forming methods like dry etching, hotembossing and nanoimprint.

A stainless steel needle as the atomizing electrode 104 was mounted onthe inside of the container 101. The length of the stainless steelneedle was 3 mm. The maximum diameter of the stainless steel needle was0.79 mm, while the minimum diameter was 0.5 mm. The stainless steelneedle had a ball having a 0.72 mm diameter at the tip thereof to stablyproduce charged microparticles. Further, the ball has a semisphericalprojection having 100 μm diameter at the tip thereof. One edge of theatomizing electrode 104 was connected to a lead for voltage application.The atomizing electrode 104 was mounted on the bottom of the container101. The tip of the atomizing electrode 104 was mounted to extendupwardly.

A thermoelectric element as the primary refrigerator 105 was mountedadjacent to the atomizing electrode 104. The size of the thermoelectricelement was 14 mm×14 mm×1 mm. The thermoelectric element had 0.9 W ofmaximum endotherm and 69° C. of maximum temperature difference. Thesurface to be chilled in the thermoelectric element was coated withceramic. Since the surface of such ceramic has fine rough structure andporous structure, it can effectively chill any subject to be contactedtherewith. Primary refrigerator 105 was connected to the atomizingelectrode 104 with a thermal conductive paste.

Opposite electrode 106 was mounted by making 3 mm space from the tip ofthe atomizing electrode 104. As the opposite electrode 106, circularstainless plate having 12 mm outer diameter, 8 mm inner diameter and0.47 mm thickness was utilized. One edge of the opposite electrode 106was connected to a lead for voltage application.

A stainless steel needle as the capture electrode 107 was mounted atadjacent to the opposite electrode 106. Length of the stainless steelneedle was 3 mm. Maximum diameter of the stainless steel needle was 0.79mm, while the minimum diameter of which was 0.5 mm. Then the stainlesssteel needle had a ball having 0.72 mm diameter at the tip thereof.Further, the ball has semispherical projection having 100 μm diameter atthe tip thereof. Tip of the capture electrode 107 was mounted to directtoward downwardly. One edge of the capture electrode 107 was connectedto a lead for voltage application.

A thermoelectric element as the secondary refrigerator 108 was mountedadjacent to the capture electrode 107. The size of the thermoelectricelement was 14 mm×14 mm×1 mm. The thermoelectric element had 0.9 W ofmaximum endotherm and 69° C. of maximum temperature difference. Thesurface to be chilled in the thermoelectric element was coated withceramic. Since the surface of such ceramic has fine rough structure andporous structure, it can effectively chill any subject to be contactedtherewith. Secondary refrigerator 108 was connected to the captureelectrode 107 with thermal conductive paste.

Operation procedures of the electrostatic atomizer are as follows.

During introduction of the gaseous sample, the gas sample was injectedinto the container 101 through the inlet 102. The container 101according to this example has 6.5 ml of volume and the gaseous samplewas injected thereinto utilizing a flow rate of 500 ml/min.

According to this example, the gaseous sample was prepared bysuccessively introducing dry nitrogen gas into water and 0.3% aceticacid solution and bubbling those.

During introduction of the gaseous sample, prior to injection of thegaseous sample into the container 101, the container 101 had been filledwith dry nitrogen gas.

Then, during introduction of the gaseous sample, the excessive gaseoussample was exhausted through outlet 103.

Then, the atomizing electrode 104 was primarily chilled with athermoelectric element. Temperature of the atomizing electrode 104 was26° C. prior to the operation and was decreased to 15° C. 30 secondslater. The temperature of the atomizing electrode 104 was determinedwith a K-type thermocouple. Preferably, the temperature of the atomizingelectrode 104 is maintained at the condensation point of water vapour orless.

Then, during production of the primary condensate, the primarycondensate 204 was going to be formed on the outer peripheral surface ofthe atomizing electrode 104 at 5 seconds after commencement of operationof the thermoelectric element. Although the diameter of liquid dropletsis 10 μm or less at the early stage of forming the primary condensate204, they increase in size and sufficient amounts thereof could be takenat 10 seconds after commencement of operation of the thermoelectricelement. Forming of the primary condensate 204 on the atomizingelectrode 104 was observed with microscope (KEYENCE, VH-6300).

Next, in producing the charged microparticles, the primary condensates204 were converted into numerous charged microparticles 205. Chargedmicroparticles 205 were produced with electrostatic atomization. Asstated in the foregoing Embodiment 1, although corona discharge wasgenerated at early stage of such electrostatic atomization, the presentdisclosure may include it in producing the charged microparticles.

In view of stability on the charged microparticles 205, the diameter ofcharged microparticles 205 should preferably be adjusted within from 2nm or more to 30 nm or less. Charged microparticles 205 exist preferablyindividually, but they may also consist of the combined pluralmicroparticles.

During production of the charged microparticles, 5 kV direct current(DC) was applied between the atomizing electrode 104 and the oppositeelectrode 106. In this case, the atomizing electrode 104 was used as acathode, while the opposite electrode 106 was used as an anode. Althougha similar effect was confirmed when the atomizing electrode 104 was usedas an anode and the opposite electrode 106 was used as a cathode, theprocess for producing the charged microparticles was relativelyunstable.

During production of charged microparticles, a conical water column,referred to as a Taylor cone, was formed at the tip of the atomizingelectrode 104 and numerous charged microparticles containing chemicalsubstances were released from the tip of the water column. FIG. 11 isthe schematic view illustrating a Taylor cone and a method for producingthe charged microparticles. Primary condensates 302, which form theTaylor cone 301, were successively transferred toward the tip of theatomizing electrode 104. Charged microparticles 303 were formed from tipof the tail cone 301 where the electrical field is concentrated.

Then, during production of the charged microparticles, electric currentflowed across between the atomizing electrode 104 and the oppositeelectrode 106 was determined. When excessive electric current flowedtherebetween, the voltage to be applied between the atomizing electrode104 and the opposite electrode 106 was eliminated or reduced.

Further, during application of the voltage, 500V of direct current (DC)was applied between the opposite electrode 106 and the capture electrode107. By applying such voltage, charged microparticles 205 can becaptured adjacent to the tip of the capture electrode 107 with staticelectricity. According to this EXAMPLE, positive voltage was applied tothe capture electrode 107 for the opposite electrode 106. Voltage to beapplied between the opposite electrode 106 and the capture electrode 107should preferably be adjusted to from 0 V or more to 5 kV or less, morepreferably from 0 V or more to 500V or less. When the chargedmicroparticles 205 are negatively charged, it is most preferable toapply a positive voltage to the capture electrode 107.

Then, the capture electrode 107 was secondary chilled with the secondaryrefrigerator 108. Temperature of the capture electrode 107 was 26° C.prior to this operation and was decreased to 15° C. 30 seconds later.Temperature of the capture electrode 107 was determined with a K-typethermocouple. Preferably, the temperature of the capture electrode 107is maintained at the condensation point of water vapour or less. Byapplying voltage to the capture electrode 107 and secondary chilling thesame, substantially all of the charged microparticles 205 can be chilledadjacent to the tip of the capture electrode 107.

During production of the secondary condensate, secondary condensate 206had been taken by condensing the charged microparticles 205 adjacent tothe capture electrode 107. Preferably, the temperature of the captureelectrode 107 should be changed appropriately according to an amount ofthe secondary condensate 206 produced. In view of the life expectancy ofthe charged microparticles 205, production of the secondary condensateshould be initiated within at least 10 minutes from commencement ofproduction of the charged microparticles.

FIG. 12( a) is an exemplary schematic view illustrating the captureelectrode 107 at the step of preparing secondary condensate, while FIG.12( b) is a photograph of the tip of the electrode taken by a lightmicroscope. Obviously from FIGS. 12( a) and 12(b), the secondarycondensate 401 can be captured adjacent to the tip of the captureelectrode 107. Spread of liquid droplet had been prevented, because thesecondary condensate 401 charged static electricity. Further, since thetip of the capture electrode 107 was directed downwardly, spread ofliquid droplet had also been prevented due to gravity applied to thesecondary condensate 401.

After producing the secondary condensate, about 1 μl of secondarycondensate 206 was accumulated adjacent to the tip of the captureelectrode 107. Two minutes was necessary from the introduction of thegaseous sample to the production of the secondary condensate.

In order to confirm the presence of acetic acid in the secondarycondensate 206, the secondary condensate 206 was removed with a syringeand was subjected to gas chromatograph assay. The assay was performedwith GC-4000 from G.L. Science.

FIG. 13 illustrates the assay result on the secondary condensate 206.The vertical axis corresponds to the peak area of gas chromotagram onacetic acid wherein the larger peak area indicates the higher aceticacid concentration in the secondary condensate 206. The horizontal axiscorresponds to voltage V_(c) to be applied to capture electrode 107 forthe opposite electrode 106. Capture voltage V_(c) should be denoted asplus, when the opposite electrode is the cathode and the captureelectrode is the anode.

In is clear from FIG. 13 that the secondary condensate 206 containedacetic acid. Acetic acid concentration in the secondary condensate 206tended to be increased according to the larger capture voltage V_(c), inparticular, acetic acid concentration in the secondary condensate 206was approximately double in comparison V_(c)=500V with V_(c)=0V. Thisindicated that the present disclosure offered the secondary effect ofconcentrating electrostatically atomized solution.

The result of FIG. 13 indicated that it is effective to secondary chillthe capture electrode 107 after voltage is applied to the same. Resultof V_(c)=500V was obtained by applying voltage to the capture electrode107 and secondary chilling the same. Result of V_(c)=0V was obtained bysecondary chilling the capture electrode 107 and applying voltage to thesame. The concentration of the secondary condensate 206 produced byapplying voltage to the capture electrode 107 and secondary chilling thesame was higher than that produced by secondary chilling the captureelectrode 107 and applying voltage to the same. It is thereforepreferable to secondary chill the capture electrode 107 after voltage isapplied to the same.

Assay conditions were as follows. Capillary column was employed as assaycolumn. Capillary column has an inner diameter of 0.53 mm and a lengthof 30 m. Helium was used as the carrier gas. Temperature of an oven wasset for 160° C. Temperature of injection and of hydrogen flameionization detector (FID) were respectively set for 250° C.

After completing the assay, the capture electrode 107 was detached fromthe container 101 and was rinsed with methanol.

Then the capture electrode 107 was heated to remove the secondarycondensate 206 on the capture electrode 107. Thermoelectric element wasused to heat the capture electrode 107. The thermoelectric element usedin this step is the same type of element utilized to chill the captureelectrode 107 to produce the secondary condensate. Voltage polarity tobe applied to the thermoelectric element to heat the capture electrode107 is reverse to that necessary to chill the capture electrode 107.

Further, in the production of charged microparticles and application ofvoltage, the capture electrode 107 was destaticized. Suchdestaticization was performed by grounding the capture electrode 107.

Then, from the introduction of the gaseous sample to the production ofthe secondary condensate, the temperature of the opposite electrode 106was maintained at the condensation point of water vapour or higher.Thereby, no condensate appeared on outer peripheral surface of theopposite electrode 106.

Example 2

Description of system employed herein is intentionally omitted, becausethe system is identical to that of Example 1. Accordingly, onlyoperation procedures of the electrostatic atomizer will be describedbelow.

During introduction of the gaseous sample, it was injected into thecontainer 101 through the inlet 102. The container 101 according to thisexample has 6.5 ml of volume and the gaseous sample was injectedthereinto with a flow rate of 500 ml/min.

According to this example, the gaseous sample was prepared bysuccessively introducing dry nitrogen gas into water and 0.3% aceticacid solution and bubbling those.

During introduction of the gaseous sample, prior to injection of thegaseous sample into the container 101, the container 101 had been filledwith dry nitrogen gas.

Then, during introduction of the gaseous sample, the excessive gaseoussample had been exhausted through outlet 103.

Then, the atomizing electrode 104 was primarily chilled with athermoelectric element. Temperature of the atomizing electrode 104 was26° C. prior to the operation and was decreased to 15° C. 30 secondslater. Temperature of the atomizing electrode 104 was determined with aK-type thermocouple. Preferably, the temperature of the atomizingelectrode 104 is maintained at the condensation point of water vapour orless.

Then, during production of the primary condensate, the primarycondensate 204 was going to be formed on the outer peripheral surface ofthe atomizing electrode 104 at 5 seconds later from commencement onoperation of the thermoelectric element. Although the diameter of liquiddroplets is 10 μm or less at the early stage of forming the primarycondensate 204, they increase and sufficient amounts thereof could betaken at 10 seconds after commencement of operation of thethermoelectric element. Forming of the primary condensate 204 on theatomizing electrode 104 was observed with microscope (KEYENCE, VH-6300).

Prior to producing the charged microparticles, the valves 109 a and 109b equipped with the inlet 102 and the outlet 103 respectively wereclosed. Thereby, introduction of the gaseous sample 203 into thecontainer 101 was terminated.

Next, in the production of the charged microparticles, the primarycondensates 204 were converted into numerous charged microparticles 205.Charged microparticles 205 were produced with electrostatic atomization.As stated in the foregoing Embodiment 1, although corona discharge wasgenerated at the early stage of such electrostatic atomization, thepresent disclosure may include it in producing of the chargedmicroparticles.

In view of stability on the charged microparticles 205, diameter ofcharged microparticles 205 should preferably be adjusted within from 2nm or more to 30 nm or less. Charged microparticles 205 exist preferablyindividually, but they may also consist of the combined pluralmicroparticles.

Then, during production of charged microparticles, 5 kV direct current(DC) was applied between the atomizing electrode 104 and the oppositeelectrode 106. In this case, the atomizing electrode 104 was used as acathode, while the opposite electrode 106 was used as an anode.

During production of charged microparticles, a conical water column,referred to as a Taylor cone, was formed at the tip of the atomizingelectrode 104 and numerous charged microparticles containing chemicalsubstances were released from the tip of the water column.

Then, during production of charged microparticles, it was determinedthat electric current flowed across between the atomizing electrode 104and the opposite electrode 106. When excessive electric current flowedtherebetween, voltage to be applied to between the atomizing electrode104 and the opposite electrode 106 was eliminated or reduced.

Further, during application of the voltage, 500V of direct current (DC)was applied between the opposite electrode 106 and the capture electrode107. By applying such a voltage, charged microparticles 205 can becaptured adjacent to the tip of the capture electrode 107 with staticelectricity. According to this EXAMPLE, positive voltage was applied tothe capture electrode 107 for the opposite electrode 106. Voltage to beapplied between the opposite electrode 106 and the capture electrode 107should preferably be adjusted within the range from 0 V or more to 5 kVor less, more preferably from 0 V or more to 500V or less. When thecharged microparticles 205 are negatively charged, it is most preferableto apply positive voltage to the capture electrode 107.

Then, the capture electrode 107 was secondary chilled with the secondaryrefrigerator 108. Temperature of the capture electrode 107 was 26° C.prior to the operation and was decreased to 15° C. 30 seconds later.Temperature of the capture electrode 107 was determined with a K-typethermocouple. Preferably, temperature of the capture electrode 107 ismaintained at the condensation point of water vapour or less.

During production of the secondary condensate, secondary condensate 206had been taken by condensing the charged microparticles 205 adjacent tothe capture electrode 107. Preferably, temperature of the captureelectrode 107 should be changed appropriately according to an amount ofthe secondary condensate 206 produced. In view of life expectancy of thecharged microparticles 205, production of the secondary condensateshould be initiated within at least 10 minutes from commencement ofproduction of the charged microparticles.

By producing the foregoing secondary condensate, approximately 1 μl ofthe secondary condensate could be accumulated adjacent to the tip of thecapture electrode 107.

Example 3

Description of the system employed herein is intentionally omitted,because the system is identical to that of Example 1. Accordingly, onlyoperation procedures of the electrostatic atomizer will be describedbelow.

During introduction of the gaseous sample, the gaseous sample wasinjected into the container 101 through the inlet 102. The container 101according to this example has 6.5 ml of volume and the gaseous samplewas injected thereinto with a flow rate of 500 ml/min.

According to this example, the gaseous sample was prepared bysuccessively introducing dry nitrogen gas into water and 0.3% aceticacid solution and bubbling those.

During introduction of the gaseous sample, prior to injection of thegaseous sample into the container 101, the container 101 had been filledwith dry nitrogen gas.

Then, during introduction of the gaseous sample, the excessive gaseoussample had been exhausted through outlet 103.

Prior to the primary chill, the valves 109 a and 109 b equipped with theinlet 102 and the outlet 103 respectively were closed. Thereby,introduction of the gaseous sample 203 into the container 101 wasterminated.

Then, the atomizing electrode 104 was primarily chilled with athermoelectric element. Temperature of the atomizing electrode 104 was26° C. prior to the operation and was decreased to 15° C. 30 secondslater. Temperature of the atomizing electrode 104 was determined with aK-type thermocouple. Preferably, temperature of the atomizing electrode104 is maintained at the condensation point of water vapour or less.

Then, during production of the primary condensate, the primarycondensate 204 was going to be formed on the outer peripheral surface ofthe atomizing electrode 104 5 seconds after commencement of operation ofthe thermoelectric element. Although the diameter of liquid droplets is10 μm or less at the early stage of forming the primary condensate 204,they increase and sufficient amounts thereof could be taken at 10seconds after commencement of operation of the thermoelectric element.Forming of the primary condensate 204 on the atomizing electrode 104 wasobserved with microscope (KEYENCE, VH-6300).

Next, in the producing of the charged microparticles, the primarycondensates 204 were converted into numerous charged microparticles 205.Charged microparticles 205 were produced with electrostatic atomization.As stated in the foregoing Embodiment 1, although corona discharge wasgenerated at early stage of such electrostatic atomization, the presentdisclosure may include it in producing of the charged microparticles.

In view of stability of the charged microparticles 205, the diameter ofcharged microparticles 205 should preferably be adjusted within therange from 2 nm or more to 30 nm or less. Charged microparticles 205exist preferably individually, but they may also consist of the combinedplural microparticles.

Then, during production of charged microparticles, 5 kV direct current(DC) was applied between the atomizing electrode 104 and the oppositeelectrode 106. In this case, the atomizing electrode 104 was used as acathode, while the opposite electrode 106 was used as an anode.

During production of charged microparticles, a conical water column,referred to as a Taylor cone, was formed at the tip of the atomizingelectrode 104 and numerous charged microparticles containing chemicalsubstances were released from the tip of the water column.

Then, during production of charged microparticles, it was determinedthat electric current flowed across between the atomizing electrode 104and the opposite electrode 106. When excessive electric current flowedtherebetween, the voltage to be applied to between the atomizingelectrode 104 and the opposite electrode 106 was eliminated or reduced.

Further, during application of the voltage, 500V of direct current (DC)was applied to between the opposite electrode 106 and the captureelectrode 107. By applying such a voltage, charged microparticles 205can be captured adjacent to the tip of the capture electrode 107 withstatic electricity. According to this EXAMPLE, positive voltage wasapplied to the capture electrode 107 for the opposite electrode 106.Voltage to be applied between the opposite electrode 106 and the captureelectrode 107 should preferably be adjusted to from 0 V or more to 5 kVor less, more preferably from 0 V or more to 500V or less. When thecharged microparticles 205 are negatively charged, it is most preferableto apply a positive voltage to the capture electrode 107.

Then, the capture electrode 107 was secondary chilled with the secondaryrefrigerator 108. Temperature of the capture electrode 107 was 26° C.prior to the operation and was decreased to 15° C. 30 seconds later.Temperature of the capture electrode 107 was determined with a K-typethermocouple. Preferably, temperature of the capture electrode 107 ismaintained at the condensation point of water vapour or less.

During production of the secondary condensate, secondary condensate 206had been taken by condensing the charged microparticles 205 adjacent tothe capture electrode 107. Preferably, temperature of the captureelectrode 107 should be changed appropriately according to an amount ofthe secondary condensate 206 produced. In view of life expectancy of thecharged microparticles 205, production of the secondary condensateshould be initiated within at least 10 minutes from commencement ofproduction of the charged microparticles.

By producing the foregoing secondary condensate, approximately 1 μm ofthe secondary condensate could be accumulated adjacent to the tip of thecapture electrode 107.

It is obvious to one skilled in the art to predict many modificationsand variations upon consideration of the disclosure herein. Theforegoing disclosure should therefore be interpreted as an illustration.Modifications regarding the details of disclosed embodiments may be madewithout departing from the spirit of the present disclosure.

INDUSTRIAL APPLICABILITY

Since a method for collecting gaseous sample according to the presentdisclosure can prevent the capture electrode from spreading solutionelectrostatically atomized thereon, it would be effective to use whereintrace components in the gaseous sample have to be assayed. The methodcan be applied to a field of environment, chemical engineering, foodprocessing and medicine in the form of, for example, but not limited to,a monitor for air pollution or water pollution and a biomarker assaydevice.

1. A method for collecting a gaseous sample with an electrostaticatomizer, comprising: preparing the electrostatic atomizer comprising asealable container, an inlet for the gaseous sample mounted at a part ofthe container, an outlet for the gaseous sample mounted at another partof the container, an atomizing electrode mounted in the container, aprimary refrigerator to chill the atomizing electrode, an oppositeelectrode mounted in the container and having a slit, an acicularcapture electrode opposed to the opposite electrode through the slitpositioned therebetween, and a secondary refrigerator to chill thecapture electrode, introducing the gaseous sample into the containerthrough the inlet, chilling the atomizing electrode with the primaryrefrigerator, preparing a primary condensate from the gaseous sample onan outer peripheral surface of the atomizing electrode, preparingcharged microparticles from the primary condensate with electrostaticatomization, applying voltage to the capture electrode for the oppositeelectrode, chilling the capture electrode with the secondaryrefrigerator, and preparing a secondary condensate from the chargedmicroparticles at a position adjacent to the tip of the captureelectrode.
 2. The method according to claim 1 wherein the introductionof said gaseous sample is completed on or before initiation of preparingcharged microparticles.
 3. The method according to claim 1 wherein thetip of said capture electrode is directed downwardly.
 4. The methodaccording to claim 1 wherein said capture electrode is chilled with saidsecondary refrigerator to a condensation point of water vapor or less.5. The method according to claim 1 wherein said secondary refrigeratoris a thermoelectric element.
 6. The method according to claim 5 whereina chilling surface of said secondary refrigerator is changed to aheating surface by reversing the polarity of direct voltage to beapplied to said thermoelectric element.
 7. The method according to claim1 wherein said secondary condensate is evaporated by heating saidcapture electrode.
 8. The method according to claim 1 wherein thetemperature of said opposite electrode is kept at a condensation pointof water vapor or more.
 9. The method according to claim 1 wherein saidcharged microparticles comprises water and components of said gaseoussample.
 10. The method according to claim 1 wherein components of saidgaseous sample are volatile organic compounds.
 11. The method accordingto claim 10 wherein molecular weight of said volatile organic compoundsis not less than 15 g/mol and not more than 500 g/mol.
 12. The methodaccording to claim 1 wherein said capture electrode possesses adestaticization system.
 13. The method according to claim 1 wherein saidcapture electrode is able to connect to ground.
 14. The method accordingto claim 1 wherein the tip of said capture electrode has a reservoir toreceive said secondary condensate.
 15. The method according to claim 1wherein the tip of said capture electrode is equipped with a detectorfor chemical substances.